William b



,(NOMOM W. B. COULTER.

RELIEF VALVE FOR STAM GYLINDERS M @d Qm'wf f (Mumia, mmm,

Unirse STATES PATENT @irriteD MTILLIAM B. COULTER, OF BRISTOL, COXNECIICIVI.

RELIEF-VALVE FOR STEAM-DYLINDERS.

SPECIFICATION forming part oi' Letters Patent No. 289,071, dated November 27, 1883,

Application filed April 1'?, lx'. (No model.)

-use the same.

My invention relates to an improvement in relief-valves, the object of the saine being to provide a device of this character which shall be adapted to adjust itself to the pressure of any engine without the aid of springs or adjusting-screws, and which shall work automaticaliy to relieve an engine-cylinder of any undue pressure that maybe exerted on the same from the presence of water or cramping of the exhaust in any way and with. these ends in view my invention consists in certain novel features of construction and combinations oi' parts, as will be hereinafter described, and pointed out in the claims.

The accompanying drawing is a sectional view of my improvement.

A represents the steanrpipe, 'connected to the boiler of an engine or to the main feedpipe, which conveys the live steam tothe cylinder, and leads into the chestB of the valve. Thecasing E of this chest B is firmly secured to the main casing or barrel C by a nut, m, provided with the lip n. To the upper end of the valvestem D, and registering with the steam-chest B, is secured,by a pin, a, and screw o, the sleeve F, which acts as avalve, and which rests on the seat Z. To the lower end of the main casing C is firmly secured the lower section, G, which latter is provided with a discharge-pipe, H, and also pipes I K, leading, respectively, to the front and rear ends of the cylinder. Y

R represents a bushing, preferably made of brass, and tting snugly within the main casing C. This casing is made with a shoulder, fz', on which is seated the `upper portion of the bushing R, the lower portion of the latter projecting below the casing, and provided with a nut, p, which impinges against the lower side of the casing and keeps the said bushing down tightly on the shoulder In this bushing reciproeates the main valve-stein D, and which also affords a seat for the upper valve, F.

Srepresents a dri p-passage from the steam chest B, formed partly in the bushing R and partly in the main casing C, to allow of the escape of the condensed water in the steamchest B. At the outer end of this passage, and within the casing G, is placed a petcock (not shown) to prevent the escape of steam.

The section G is divided into two parts by the partition L. A second partition, O, subdivides the lower portion of the section G into two independent parts, said section G being thus divided into three compartments. Through the partition L, and on either side of the partition O,.is a passage, M, adapted to be opened and closed by the valve D.

Having described the construction of my improved device, I will now set forth its operation.

The pipe A allows the free passage of steam from the boiler to the chest B. rlhe pipes I K allow the passage of the pressure in the cylinder into the chambers of the section G, which remains there while the engine is in motion. Vhen the .pressure of the steam in the boiler exceeds that in the cylinder, the pressure on the upper end of the valve D will be greater than on the lower end, and thus keep the valve down tightly on the partition L and close the openings M; but when from any cause the pressure in the cylinder is in excess, the greater pressure on the lower end of the valve will force the latter up and allow the escape of the water or steam through the openings M and through the discharge H. 'When the pressure is decreased in the chest, it will again force the valve D down and close the openings M.

It will he seen that but one deviace is necessary for au engine, and when the lower end of the valve D is forced up it opens both openings M, and relieves one end of the cylinder of the steam-pressure and the other end of the water-pressure.

My improvement is simple in construction, is efficient in use, and can be applied to any engine at a slight initial cost.

Having fully described my invention, what IOO I claim as new, and desire to secure by Letters Patent, is-

l. A relief-valve provided at one end with a pipe connecting with the boiler or main feedpipe, and at the other end with two pipes connecting with both ends of the cylinder, and mechanism whereby the valve automatically relieves the cylinder of any excess of pressure, substantially as set forth.

2. rIhe combination, with avalve-casing inclosing a valve-stem having a valve at each end, of a chamber connected with the boiler, and adapted to receive one of the valves of the stem, and a chamber having a dischargeoutlet and opening into two compartments respectively connected with opposite ends of the cylinder, the openings between the chamber and compartments being simultaneously opened or closed by the oth er valve on the said valve-stein, substantially as set forth.

3. rlhe combination, with avalve-casing provided with an outlet for condensed steam and inclosing a valve-stem having a valveat each end, of a chamber connected with the boiler and arranged to receive one of the valves of the stem, and a chamber having a dischargeoutlet, the lower portion of the said chamber being divided into two independent compartments by a partition, said compartments being respectively connected with the front and 33 rear en ds of the cylinder, and also having openings leading into the upper 'portion of said chamber, said openings being adapted to be opened and closed by the other valve on the stem, substantially as set forth.

et. rlhe combination, with a valve-casing, C, provided with opening S, shoulder t', and bushing R, said casing inclosing a valve-stem provided with a valve at each end, of a chamber connected to the boiler and arranged to receive one of the valves of the stem, and a chamber provided with an outlet and the partitions O and L, the latter provided with the openings M, adapted to be opened and closed by VILLIAM B. COULTER.

'Wit/messes:

EDWARD A. PORTER, BENJ. F. HAWLEY. 

